Heating unit end mounting



April 15, 1958 w. D. KELLY HEATING UNIT END MOUNTING 2 Sheets-Sheet 1Filed Nov. 1. 1954 April 15, 1958 w. D. KELLY HEATING UNIT END MOUNTING2 Sheets-Sheet 2 Filed NOV. 1, 1954 @1M/0222 ag??? BY Nm fh )Ww a@HEATING UNIT END MOUNTING William D. Kelly, Western Springs, Ill.,assigner to yli`uttle & Kift, Inc., Chicago, Ill., a corporation oillliinois Application November 1, 1954, Serial No. 465,864

9 Claims. (Cl. 219-37) This invention relates to electrical heatingunits wherein the heating resistor extends lengthwise within andelectrically insulated from a tubularsheath which is bent in the form ofa flat winding, as for example in a tlat spiral form such as commonlyused for surface heating units of electric ranges, the invention havingreference more particularly to the mounting of the ends of such heatingunit.

Such heating units, and especially range surface heating units, areusually pivotally mounted to swing upwardly from the normal position ofuse in order to afford access to the underside of the heating unit andto parts underneath the heating unit, and it is customary ot make suchpivotal connection to the sheath at or in the vicinity of the placewhere the resistor terminals project there* fromso -that the conductors,which are connected to the terminals to supply current to the resistor,do not interfere with and are not appreciably affected by the pivotalmovement of the heating unit.

Such heating units, however, are subjected to a wide range oftemperature change which causes lengthwise expansion and contraction ofthe sheath, and as diterential expansion and contraction occurs at theinner and outer sides respectively of the convolutions or bends of thewinding, the latter tends to expand and contract in the plane in whichit is bent and accordingly it is important that the ends of the sheathbe free to move relatively so as to avoid distorting strains which wouldother wise be imposed on the unit.

To permit such freedom of the sheath ends to move relatively the heatingunit of Tuttle Patent 2,508,582 has the flat winding thereof restingloosely on a supporting spider and the resistor or resistors arearranged in the sheath so that the terminals are at one end of thesheath, and the heating unit is pivotally mounted at that end of thesheath, the other end thereof being remote from and unattached to thepivotal mounting and thus freely movable in the expansion andcontraction of the heating unit.

The pivotal mounting of that Tuttle patent also has the advantage thatthe end portion of the sheath extends axially of and constitutes a partof the pivoting structure or hinge and the terminals extend from thepivoted sheath end in an axial direction and suiciently close to theaxis of pivotal movement so that in the pivotal movement of the heaterthe conductors connected to the terminals are merely subjected to aslight twist and no bending of the conductors occurs which mighteventually cause breakage thereof.

In some cases, however, and especially in heating units having a sheathof small diameter, it is desirable or even necessary to provideterminals at each end of the sheath and'in such cases it not only isnecessary to locate both ends of the sheath at the place of pivotalmounting for connection of the current supply conductors to theterminals at both ends of the sheath, but it is also important tosupport both ends of the sheath at the place of pivotal mounting as thesmall diameter sheath does not have "United States Patent O ICCsufficient rigidity to maintain the desired flat winding shape withoutsuch support at both ends thereof.

Unless, however, the thus supported ends are free to move relatively ina direction to accommodate the differential expansion and contraction ofthe inner and outer sides respectively of the convolutions or bends ofthe winding, obiectionable distorting strains are imposed on the heatingunit.

The principal objects of the present invention are to provide animproved pivotal mounting of the opposite ends of a tubular sheathedheating unit; to hold both ends of the sheath in a manner to positivelymaintain the winding of the heating unit in the desired flat form; topermit relative movement of the pivoted opposite ends in conformity withthe expansion and contraction of the heating unit; to provide a conjointmounting of the sheath ends which is simple and convenient; to locatethe sheath ends within and axially of the hinge and with the currentsupply conductors connected to the terminals at a place where bending ofthe current supply conductors is minimized; and to provide a hingemounting which is adapted to accommodate the sheath ends of a heatingunit conposed of several sheath sections, these and other objects beingaccomplished as pointed out more particulariy hereinafter and as shownin the accompanying drawings in which:

Fig. l is a top View of a heating unit assembly constructed inaccordance with the present invention;

Fig. 2 is a side view of the heating unit assembly of Fig. 1 withportions broken away at the hinge to show details of the construction;

Fig. 3 is a View taken on the line 3-3 of Fig. 2 looking at the terminalend of the heating unit when the latter is in the normal operatingposition;

Fig. 4 is a sectional view on the line 4 4 of Fig. 2; and

Fig. 5 is a view similar to Fig. 4 but showing the illustrated parts inthe position they occupy when the heating unit is tilted upwardly to theupraised position.

Heating units of the type to which this invention relates are usedextensively in electric ranges, especially as surface heating unitsthereof, and it is customary to incorporate the heating unit in anassembly. which includes a mounting ring by which the heating unit issupported in or at an opening in the range top.

Such assembly is shown in the accompanying drawings in which thereference numeral i0 indicates the heating unit as a whole and 11 themounting ring, a portion of the range top being also shown at 12 whichhas an open* ing 13 therethrough in which the assembly is mounted.

The mounting ring 1l has a skirt portion 31A which extends downwardlythrough the range top opening i3 and is provided at the bottom with adrip pan l5 which slopes inwardly to a central opening 16, and said ringil is provided at the top with an annular ange or rim f1.7 which extendsaround the upper end of the skirt portion 14 and rests on the portion ofthe range top il?. around the opening 13 to support the assembly.

The drip pan 15, which serves also as a heat reilector for the heatingunit thereabove, may be made as an integral part of the ring 1i. or as aseparate part and removable from the ring as is well known in the art,the latter form being shown in the drawing, and the center opening 16thereof serves not only for drainage but also for ventilation of theinterior of the ring.

Heating units of electric ranges are sometimes made ot a single sheathedsection or heating element, for example, as shown in Tuttle Patent2,368,051, which is bent into the desired at winding form, whereasothers are made of several sheathed sections or heating elements, forexample, as shown in Tuttle Patent 2,467,348, each having bent 3portions or coils arranged conjointly to form the flat winding.

The latter form of heating unit is shown herein having two sheathedsections or heating elements which are indicated as a whole respectivelyat'18 and 19 and each is formed with coils, which are indicatedrespectively4 at lila and 19e, and are intercalated with the coils ofthe other sheathed section or heating element so that conjointly theyconstitute the flat winding of the heating unit.

Each of said heating elements 18 and Fri-com ri tubular sheath 29 havinga heating resistance 3i. extendlengthwise therein and embedded incompacted electrical insulating material 2.2 in a manner Well l" SCS l.

known' in the art, and each resistance 21 is provided at each end with aterminal which extends outwardly throvh and insulated from therespective end portion of sheath- 2Q thereof and projects suiiicientlytherebeyond for attachment thereto of conductors through which currentis supplied to that resistor.

The aforesaid end portions of the sheath 2t? of the heating element areindicated respectively at 23 and 2o and the term als therein areindicated respectively at 25 and 2d e end portions of the sheath 2@ ofthe heating element are indicated respectively at 27 and 2S and theterminals therein are indicated respectively at 29 and 3d.

rthe winding, composed of the intercalated coils 18s and 92, is locatedwithin the mounting ring 11 at 'the top thereof so that it projectssuiiiciently above the mounting ring as shown in Fig. 2 to support a panor utensil thereon, and is supported on, but unattached to, a spider 31which is removably mounted within the ring 11.

rhis spider 31 comprises three arms 32, 33 and 34 the inner ends ofwhich are securely connected to one another underneath an attachedcenter disk to which the spider indicating reference numeral is appliedand thc outer ends of the arms 32 and 33 rest on shoulders 35 which arepressed inwardly from the skirt portion 14 of the mounting ring 11. Theother spider arm 34- has a reduced tongue extension 36 (see Fig. 2) atthe other end which is engaged in and projects through an opening 37 inthe skirt portion 14 to support the outer end of said arm 34, thearrangement being such that when the tongue extension 36 is engaged inthe opening 37 the outer ends of the arms 32 and 33, by reason of theircontinement within the skirt portion 14, are positioned by the tongue 3dengagement with the opening 37 to be supported on and retained againstdisplacement from the shoulders 35.

The tlat winding of the present heating unit, comprising theintercalated coils 13a and 19a, is hinged to swing upwardly from itsnormal position on the spider 3l. to a substantially upright position atone side of the mounting ring li and in substantially the same manner asthe beating unit swings upwardly'in Tuttle Patent 2,5tl6,554, it beinean important feature of the present invention, however, that the sheathsection or sections of the heating have terminals at both ends thereofand both ends of said section or sections are held, at the place ofpivoting, in a manner to retain the coils of the winding tirinly in theform of a fiat winding and these sheathed ends extend conjointly in thesame direction at the place of hinging and along the pivotal axis of thehi ge.

it is also an important feature that although the opposite end portionsof the sheath or sheaths are held at the 'nge location in a manner 'toprovide sulllciently ntial support theerof to maintain the heating unitcerti-intv in the at winding form, the opposite of the sheath or sheathsare relatively mova direction to compensate for and permit freedom ofexpansion and contraction of the coils of the winding that occurs in thechanges of temperature to which the coils are subjected.

is accomplished in the illustrated structure by lo` eating all of theend portions 23, 24, 27 and 28 at the periphery of the windings 18a',19a, and at the same peripheral place, and extending these endsconjointly and in the same direction tangentially from the winding anddownwardly through an opening 38 in the skirt portion 14 to a placeoutside said skirt portion and below the level of the mounting ringflange 17 and the range top 12 and pivotally mounting these ends at thelatter place in a manner which permits at least one end of eaclrheatingelement E? in a direction to compensate for the expansion'and'contraction of the coils 18a and 19a.

The ends 23 and 24 are merely continued tangentiall in parallel relationfrom the respective` coils 18e and 19a, as shown in Fig. l, and both ata corresponding downward slope through the opening 38, the slope of bothbeing the same as the slope of the end 23 in Fig. 2, whereas the otherends 24 and 23 are brought over underneath the coils 18a and 19a, asindicated respectively at 39 andA 4t', to the place at the periphery ofthe winding where the ends 23 and 27 extend tangentially and slopedownwardly therefrom, and said ends 24- and Ztl extendv likewisetangentially and downward underneath the ends 23 and 27 in parallelrelation therewith and through the opening 38.

These end portions 23, 24, 27 and 28, beyond the opening 38, extendthrough and are mounted in a tubular sleeve 41 which is journaled torotate in a bearing which is mounted on the skirt portion 14 at theexterior thereof.

The said bearing is composed of two parts one of which, indicated at 42,is of substantially the same lengthy as the sleeve 41, as shown in Fig.2, and ofv rectangular shape in cross section but open at one side, asshownin Fig. 3. The other part of the said bearing, as shown at 43, is aplate which closes the open side of the bearing part 42 and thesebearing parts 42 and 43 are conjointly secured to a bracket 44 which inturn is securedl to the outer side of the skirt portion 14 so as to holdthe bearing 42, 43 at an inclination corresponding to the slope of theends 23, 24, 27 and 28 and in the line oftangency of the said ends withrespect to the winding 18a, 19a.

The bracket 44 is provided with flanges 45 which conform to and arepreferably spot welded as at 46 tothe skirt portion and said bracket hasother anges 47 to which the bearing parts 42 and 43 are secured byscrews 48, as shown in Figs. 2 and 3.

The width of the bearing opening between the plate and the opposite sideof the bearing part 42 is such as to conne the sleeve 41 quite closelytherebetween, as shown in Fig. 3, but in thevertical direction thesleeve 41 is loosely coniined in the bearing opening, as also shown inFig. 3, to permit sufficient tilting of the heating unit ends 23, 24, 27and 28 in the direction of their length to insure that the coils 18a and19EL lie dat on the supporting spider 31 when the heating unit is in thenormal position of operation.

The sleeve 41, which is iournaled in the bearing 42, 43 as aforesaid, isof such internal diameter that the heating unit ends 23, 24, 27 and 23loosely occupy the interior thereof, the upper ends 23 and 27, however,being clamped securely to the top of the sleeve by a clamping member 49which underlies said ends 23 and 27, and has threaded engagement with ascrew 50 which extends downwardly through the top of the sleeve 41 andbetween the ends 23 and 27 and serves in conjunction with the clampingmember 49 to hold the ends 23 and 27 iirmly in a xed position in thesleeve 41.

The said ends 24 and 2S are, however, loosely contained in the bottom ofthe sleeve 41 and not only are free to move longitudinally therein buthave sutlcient latitude of sidewise movement in any direction so thatthere is no cramping or binding thereof in the sleeve 41 which mightinterfere with the freedom of longitudinal movement.

Thus, although the respective ends 23 and 27 of the heating elements 18and 19 are xed in the pivoted sleeve` and 19, although hingedly mounted,to mover 41 and the respective ends 24 and 28 are conned and heldsufficiently by said sleeve 41 to contribute substantial support of theheating unit, the said ends 24 and 28 are sufficiently free so that theyare movable relatively with respect to the tixed ends 23 and 27 and in amanner to respond to expansion and contraction of the heating unit underthe changes of temperature to which it is subjected. '1" he principalexpansion and contraction of the heating unit is in the plane of thecoils 13a and 19a and, although the ends 24 and 28 and the sleeve 41 areinclined with respect to that plane, the freedom of movement of the ends24 and 28 in the sleeve 41 is such that their permissible movement isnot solely in the direction of their length but suiliciently sidewise sothat at their acute angularity to the plane of the coils 1S and 19,their movement is substantially in accord with the expansion andcontraction of the heating unit.

The heating unit ends Z3 and 27 are further secured to the sleeve 41 andheld in line therewith by an arm 51 which is secured at its lower end tothe sleeve and projects from the upper end thereof between the ends 23and 27 and at its upper end is secured thereto.

The clamping member 49 extends only part way of the length of the sleeve41, as shown in Fig. 2, and the arm 51, which ,is of plate stockdisposed in a vertical plane, has its lower end enlarged as indicated at52 and extending diametrically across thefupper end of the sleeve 41beyond the clamping member 49 with the heating unit ends 23 and 24 atone side of said portion 52 and the heating unit ends 27 and 2t! at theother side thereof. This portion 52 is secured in the sleeve 41 by a lug53 at the top thereof which is engaged in an opening 54- in the wall ofthe sleeve.

The arm 51 is continued a considerable distance beyond the upper end ofthe sleeve il between the heating unit ends 23 and 27 and at the upperend has a pin 55 extending therethrough which is welded as at 56 andrespectively to the underside of the heating unit ends 23 and 27.

To prevent endwise movement of the sleeve 4l in the bearing 42, 43 thescrew Sti by which the heating unit ends 23 and 27 are clamped in thesleeve, is provided with an elongated head :Se which projects through atransverse slot 59 of the bearing part 42, this slot 59 being so locatedand of such length to permit the necessary rotation of the sleeve 41 inthe bearing 42, 43 for swinging the heating unit 1t) from the normalhorizontal position on the spider 31 to an upright substantiallyvertical position at theside of the mounting ring 11. y

Preferably a latch is provided to safely retain the heating unit in theupraised position, and for this purpose the bearing part 42 is formed atits upper end with a spring tongue 60 which extends part way around thegroup of heating unit ends 23, 24, 2'7 and 28 immediately beyond theupper end of the sleeve 41 and has a bent tang portion 61 at the freeend thereof arranged to engage over one lateral edge of the enlargement52 of the arm 51, as shown in Fig. 5, when the heating unit 1d is in theupright position and by such engagement to hold the heating unit againstaccidental displacement from said upraised position thereof.

For operation of the heating unit 10, current supply conductors areconnected tothe outer exposed ends of the terminals 25, .'26, 29 and El@which are located in close proximity to the axis of pivotal movement ofthe sleeve 41 in the bearing 42, 43 and by reason thereof there is onlya slight twist of said current supply conductors when the heating unitis swung to and from the upraised position and bending of the conductorsis avoided which might eventually cause breakage thereof.

While I have shown and described my invention in a preferred form asapplied to a surface heating unit with two tubular sheathed heatingelements, it is to be understood that it is applicable to heating unitsother than those for range surface heating and to heating unitscomassiduo prising more or less than two tubular sheathed elements andthat various other changes and modifications may be made withoutdeparting from the principles of the invention, the scope of which is tobe determined by the appended claims.

What is claimed is:

l. An electric heating unit comprising at least one elongated tubularsheath containing a heating resistance which is electrically insulatedfrom the sheath and has terminals at the opposite ends of the sheath,said tubular sheath being in the form of a iiat winding which is free toexpand and contract in the plane of flatness thereof upon changes oftemperature of the heating unit, and

said sheath having the opposite end portions thereof exv tendingcorrespondingly in side by side relation in a substantially tangentialdirection from approximately the same place at the periphery of thewinding and conjointly pivoted to a support on an axis which extends inthe direction of the length of said opposite end portions the directionin which the said sheath ends extend and the axis on which they areconjointly pivoted being suciently near to horizontal to cause thewinding to swing upwardly from a horizontal plane position to a positionin an upwardly extending plane.

2. An electric heating unit comprising at least one elongated tubularsheath containing a heating resistance which is electrically insulatedfrom the sheath and has terminals at the opposite ends of the sheath,the said tubular sheath being bent in the form of a flat winding whichis free to and expands and contracts in the plane of tlatness thereofupon changes of temperature of the heating unit. and causes movement ofsaid opposite ends relatively to one another in a direction ofapproximate parallelism with said plane, said sheath having opposite endportions thereof extending correspondingly in side by side relation in asubstantially tangential direction from approximately the same place atthe periphery of the winding and at a moderate slope obliquely downwardfrom the aforesaid plane in a direction corresponding generally to thedirection of said relative movement of said opposite ends and conjointlypivoted to a support on a pivotal axis which extends in the direction ofthe length of said opposite end portions permitting the winding to swingupwardly from a horizontal plane to an upwardly extending plane.

3. An electric heating unit comprising at least one elongated tubularsheath containing a heating resistance which is electrically insulatedfrom the sheath and has terminals at the opposite ends of the sheath,the said tubular sheath being bent in the form of a hat winding which isfree to and expands and contracts in the plane of atness thereof uponchanges of temperature of the heating unit and causes movement of saidopposite ends relatively to one another in a direction of approximateparallelism with said plane, said sheath having the opposite endportions thereof extending correspondingly in side by side relation in asubstantially tangential direction from approximately the same place atthe periphery of the winding and at a moderate slope obliquely downwardfrom the aforesaid plane in a direction corresponding generally to thedirection of said relative movement of said opposite ends and conjointlypivoted to a support on a pivotal axis which extends in the direction ofthe length of said opposite end portions, said end portions which areinclined downwardly as aforesaid being pivoted at one side of the planeof the winding on an axis which is suiiiciently near to horizontal topermit the winding to swing upwardly from a horizontal plane to anupwardly extending plane.

4. An electric heating unit comprising at least one elongated tubularsheath containing a heating resistance which is electrically insulatedfrom the sheath and has terminals at the opposite ends of the sheath,the said tubular sheath being bent in the form of a flat winding whichis free to and expands and contracts in the plane of flatness thereofupon changes of temperature of the heating unit and causes movement ofsaid opposite ends `relatively to one another in a direction ofapproximatel parallelism with said plane, said sheath having theopposite end portions thereot-` extending substantially tangentially inside by side relation in the same direction from approximately the'sameplace at the periphery of the winding in a direction correspondinggenerally to the direction of said relative movement of said oppositeends and conjointly pivoted to a support on a pivotal axis which extendsin the direction of the length of said opposite end portions, one cfsaid end portions lacing iixediy secured relatively to said pivotal axisand the other of said end portions being free to move relatively to saidpivotal axis in substantially the direction in' which the sheath endsare caused to move relatively to one another by theA aforesaidexpansion` and contraction of the hat winding.

5. An electric heating unit comprising at least one elongated tubularsheath containing a heating resistance Which is electrically insulatedfrom the sheath land has terminals at the opposite ends of the sheath,said tubular sheath being in the formA of a llat winding which is freeto expand and contract in the plane of the ilatness thereof upon changesof temperature of the heating unit, said sheath having the opposite endportions thereof tending correspondingly in side by side relation in asubstantially tangential direction from approximately the same place atthe periphery of the winding and at moderate slope obliquely downwardfrom the aforesaid plane '5 and said opposite end portionsbeingcontained in and conjointly pivoted in a bearing and exten-ding inthe direction of the length of the pivotal axis thereof which issutliciently near to horizontal to permit the winding to swing upwardlyfrom a horizontal plane to an upwardly extending plane.

6. An electric heating unit comprising at least one elongated tubularsheath containing a heating resistanceV which is electrically insulatedfrom the sheath and has terminals at the opposite ends of the sheath,said tubular sheath being in the form of a ilat winding which is free toexpand and contract in the plane of the flatness thereof upon changes oftemperature of the heating unit, said sheathl having the opposite endportions thereof eirtending substantially tangentially side hy rela inthe same direction from approximately the saine at t e periphery of thewi ding, s site end seing within' extending lei turnable in a bearingone o osito end pci being fixed insaid` sleeve and the other end portionfree to move therein.

7. An electric heating unit comprising a plurality of elongated tubularsheaths each having coils thereof of dat spiral shape intercalated withcoils of another of .t-

said sheaths and conjointly constituting ya flat Winding, each sheathcontaining a heating resistance which is electrically insulated from therespective sheath and has terminals at the respective'opposite ends ofthe sheath, all

of said sheaths having the opposite end portions thereof l, i

extending substantially tangentially in the same direct1on fromapproximatelythe same place at the periphery of the winding and `all ofsaid end portions being in side sheath containing a heating resistancewhich is electrically insulated from the respective sheath and hasterminals at the respective opposite ends of the sheath, a mounting forsaid heating unit having an opening at the top thereof `in `which saidwinding is located and having a skirt portion extending downwardlyaround said winding, and

spider within said mounting on which said winding rests and to and fromwhich the winding is freely movable, all said sheaths having theopposite end portions thereof extending substantially tangentially inthe same direction from approximately the same place at the periphery ofthe winding through said skirt portion and therebeyond all of said endportions being in side by side relation to one another and contained ina sleeve which is turnable in a bearing which is mounted on the exteriorof said siti-rt portion, ot' said opposite end portions of each sheathbeing fixed in the sleeve and the other opposite end portion of eachsheath being free to move in the sleeve.

9. An electric heating unit comprising at least one elongate-d tubularsheath containing a heating resistance which is electrically insulatedfrom thelsheath and has terminals at the opposite ends of the sheath,the said sheath being bent in the form of a tlat spiral having aplurality of coils in the same plane and including a large outer coiland a small inner coil within the contines and yapproximately central ofthe outer coil, the outer coil having one end portion of the sheathcontinuing in a tangential direction therefrom and rectilinear and theinner coil having a longer end portion at the other end of the sheathextending downwardly from the inner coil at one side thereof andoutwardly at la lateral curvature reverse to that of said side of ltheinner coil and terminating in a rectilinear portion which is paired withand extends in the same direction as and in substantially parallel sideby side relation to and is engaged with the other rectilinear portion ina bearing to turn conjointly therein with said other rectilinearportion, the said paired rectilinear sheath end portions beingsufliciently near to horizontal to provide a hinge connection on apivotal axis which is suiciently near to horizontal to permit thewinding to swing upwardly from a horizontal plane to an upwardlyextending plane.

References Cited in the tile of this patent UNITED STATES PATENTS2,506,554 Tuttle May 2, 1950 2,515,579 Allen July 18, 1950 2,610,281Rutenber et al Sept. 9, 1952 2,632,837 Andersen Mar. 24, 1953 2,662,158Vallorani et al. a Dec. 8, 1953 2,748,248 McOrlly May 29, 1956

